8-Methyl-6-(1-piperidinyl)-1,2,4-triazolo[4,3-b]pyridazine and its use in alleviating bronchial spasms have been described in U.S. Pat. Nos. 3,915,968 and 4,136,182. The compound has, in fact, been investigated clinically and studies have been carried out to determine urinary metabolites of this compound. Mass spectrometry techniques were used to investigate the structure of these metabolites and some of this work was described at the Bucknell lecture series (Dec. 1, 1982); at the Thirty-first Annual Conference on Mass Spectrometry and Allied Topics (Boston, 1983); at the Thirty-third Annual Conference on Mass Spectrometry and Allied Topics (San Diego, 1985); and at the Finnigan MAT Seminar Series (Cincinnati, 1985). In these presentations a number of possible metabolites were discussed. 2,3-Dihydro-1-(8-methyl-1,2,4-triazolo[4,3-b]-pyridazin-6-yl)-4(1H)-pyridi none was one of these proposed possible metabolites but the substance involved was only present in small quantities. In addition, it should be noted that the analysis was carried out on urine samples containing a mixture of metabolites rather than on the pure metabolites themselves. Thus, although 2,3-dihydro-1-(8-methyl-1,2,4-triazolo[4,3-b]pyridazin-6-yl)-4(1H)-pyridin one was proposed as a metabolite, it was not isolated in purified form. In addition, at that time, it was not possible to confirm that the structure of this proposed metabolite was correct by independent chemical synthesis. Specifically, because of the dihydropyridinone structure, such a compound could not be obtained by the synthetic procedures described in the patents referred to earlier or by any other obvious alternative procedures.